/**
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jivesoftware.smackx.pubsub.packet;

import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.PacketExtension;
import org.jivesoftware.smackx.pubsub.PubSubElementType;

/**
 * The standard PubSub extension of an {@link IQ} packet. This is the topmost
 * element of all pubsub requests and replies as defined in the <a
 * href="http://xmpp.org/extensions/xep-0060">Publish-Subscribe</a>
 * specification.
 * 
 * @author Robin Collier
 */
public class PubSub extends IQ {
	private PubSubNamespace ns = PubSubNamespace.BASIC;

	/**
	 * Returns the XML element name of the extension sub-packet root element.
	 * 
	 * @return the XML element name of the packet extension.
	 */
	public String getElementName() {
		return "pubsub";
	}

	/**
	 * Returns the XML namespace of the extension sub-packet root element.
	 * According the specification the namespace is
	 * http://jabber.org/protocol/pubsub with a specific fragment depending on
	 * the request. The namespace is defined at <a
	 * href="http://xmpp.org/registrar/namespaces.html">XMPP Registrar</a> at
	 * 
	 * The default value has no fragment.
	 * 
	 * @return the XML namespace of the packet extension.
	 */
	public String getNamespace() {
		return ns.getXmlns();
	}

	/**
	 * Set the namespace for the packet if it something other than the default
	 * case of {@link PubSubNamespace#BASIC}. The {@link #getNamespace()} method
	 * will return the result of calling {@link PubSubNamespace#getXmlns()} on
	 * the specified enum.
	 * 
	 * @param ns
	 *            - The new value for the namespace.
	 */
	public void setPubSubNamespace(PubSubNamespace ns) {
		this.ns = ns;
	}

	public PacketExtension getExtension(PubSubElementType elem) {
		return getExtension(elem.getElementName(), elem.getNamespace()
				.getXmlns());
	}

	/**
	 * Returns the current value of the namespace. The {@link #getNamespace()}
	 * method will return the result of calling
	 * {@link PubSubNamespace#getXmlns()} this value.
	 * 
	 * @return The current value of the namespace.
	 */
	public PubSubNamespace getPubSubNamespace() {
		return ns;
	}

	/**
	 * Returns the XML representation of a pubsub element according the
	 * specification.
	 * 
	 * The XML representation will be inside of an iq packet like in the
	 * following example:
	 * 
	 * <pre>
	 * &lt;iq type='set' id="MlIpV-4" to="pubsub.gato.home" from="gato3@gato.home/Smack"&gt;
	 *     &lt;pubsub xmlns="http://jabber.org/protocol/pubsub"&gt;
	 *                      :
	 *         Specific request extension
	 *                      :
	 *     &lt;/pubsub&gt;
	 * &lt;/iq&gt;
	 * </pre>
	 * 
	 */
	public String getChildElementXML() {
		StringBuilder buf = new StringBuilder();
		buf.append("<").append(getElementName()).append(" xmlns=\"")
				.append(getNamespace()).append("\">");
		buf.append(getExtensionsXML());
		buf.append("</").append(getElementName()).append(">");
		return buf.toString();
	}

}
